Thoracic aorta aneurysms have an incidence of around 5–10 per 100,000 person-years, most commonly caused by congenital disorders such as genetic connective tissue disorders or bicuspid aortic valve syndrome.1 Iatrogenic pseudoaneurysms are rare occurrences, usually as sequelae of cardiac surgeries.2
Untreated aortic pseudoaneurysms are prone to progressive dilation, which increases the risk of potentially fatal complications such as rupture or dissection.3 Aorto-right ventricular fistulas (ARVFs) are reported as sporadic congenital anomalies or a rare but potentially life-threatening complication after traumatic events or iatrogenic causes such as after transcatheter aortic valve implantation.4–6
While aortic aneurysms typically rupture into the pericardial space or pleural cavity, it is extremely rare for an aortic aneurysm to rupture into a cardiac chamber, with no prior reported cases in the literature.3 We present a unique case of a large iatrogenic pseudoaneurysm complicated by a contained rupture into the right ventricle resulting in an ARVF.
History of Presentation
A 57-year-old man was initially brought to a regional community medical center after reportedly being found unconscious. According to his family members and neighbors, the patient had felt weak for the past few days and had an episode of chest pain before being found unconscious. CT of the patient’s head and CT angiography of his head and neck, as part of a stroke workup, were inconclusive. His urine drug screen was positive for benzodiazepines, fentanyl, cannabis, and methamphetamines. An ECG was obtained, which showed nonspecific ST changes and findings consistent with non-ST elevation MI.
An emergent left heart catheterization and coronary angiography were performed at an external hospital for suspected acute coronary syndrome in the setting of typical chest pain and elevated high-sensitivity troponin levels in the hundreds. The patient was found to have non-obstructive coronary artery disease. However, during the coronary angiography, injections of the right coronary artery and staining of the aortic wall were noted, and an aortic dissection was suspected. An emergent transthoracic 2D echocardiogram (TTE) was suggestive of a possible pericardial hematoma. A CT angiogram of the aorta demonstrated a large ascending aortic aneurysm. The patient was then transferred to a tertiary care hospital for further management.
Medical History
The patient reported undergoing prior cardiac surgery around 30 years ago while he was in his late 20s for a congenital cardiovascular anatomic defect, likely a ventricular septal defect (VSD) repair. He also had a history of essential hypertension and polysubstance use, including cocaine, methamphetamines, benzodiazepines, opiates, and cannabis.
Hospital Course and Investigations
Upon arrival at the tertiary care hospital, the patient was admitted to the cardiovascular intensive care unit (ICU) due to significant hypertension and metabolic encephalopathy in the setting of an aortic aneurysm and suspected dissection and was placed on esmolol and nicardipine titratable drips to control his blood pressure and heart rate. CT angiogram of the aorta was repeated and noted a normal caliber aortic root and ascending aorta with a 6.6 × 6.1 × 5.5 cm partially thrombosed anterior ascending aortic aneurysm (Figures 1 and 2, and Supplementary Figure 1 ). The aneurysm was likely chronic with layered thrombus. It was thought to be possibly related to his prior VSD repair surgery and long-term hypertension, and polysubstance use.
On the second hospital day, the patient was more alert and following commands as metabolic encephalopathy gradually improved. He was evaluated for a possible surgical aortic aneurysm repair. On his third day in the cardiovascular ICU the patient had two episodes of sustained ventricular tachycardia for which he required electrical cardioversion and initiation of an amiodarone drip. Subsequent evaluations, including TTE and cardiac MRI, were obtained. TTE was remarkable for hyperdynamic left ventricular ejection fraction (70–75%) without wall motion abnormalities, with moderate concentric left ventricular hypertrophy and grade 2 diastolic dysfunction suggestive of hypertensive heart disease (Supplementary Figure 2 and Figure 3 ). A cardiac MRI confirmed the partially thrombosed ascending aortic pseudoaneurysm and prior pericardial patch repair of a congenital septal defect. Phase-sensitive inversion recovery imaging demonstrated no significant late gadolinium enhancement to suggest myocardial scar on cardiac MRI. A transesophageal echocardiogram was also obtained to rule out suspected aortic dissection.
Nicardipine and esmolol drips were gradually weaned off, and he was transitioned to a regimen of oral antihypertensive medications. On the night before the planned aortic aneurysm surgery, he became hypotensive and bradycardic, requiring initiation of IV pressors and placement of a transcutaneous pacemaker.
Emergent laboratory testing showed creatinine elevated to 2.1 mg/dl from 1.0 mg/dl. High-sensitivity troponin was 39,445 pg/ml C, which then trended up to 42,792 pg/ml C. The ECG was suggestive of around 2 mm upsloping ST elevations in leads II, III, and aVF with reciprocal depressions (Supplementary Figure 3 ). Due to concern for possible acute coronary syndrome, an emergent repeat transthoracic and subsequent transesophageal echocardiogram were performed, which was suggestive of new continuous flow into the right ventricle on color Doppler imaging, suggestive of a newly developed ARVF. Additionally, the right ventricular size had increased significantly from prior echocardiographic imaging, and the estimated right ventricular systolic pressure was notably increased from prior recent testing.
Management
The patient was emergently brought to the operating room for an extremely high-risk salvage aortic aneurysm repair surgery. The patient became markedly hemodynamically unstable after anesthesia induction, with a systolic blood pressure of 50 mmHg. An external cardiopulmonary bypass involving the right femoral artery and vein was obtained. A large, 2 cm diameter hole in the anterior part of the ascending aorta communicated with this large pseudoaneurysm, layered with old and new thrombus (Figures 4 and 5, and Supplementary Figure 4 ). The fistula into the RV outflow tract area was just proximal to the pulmonic valve. This was a large area measuring >4–5 cm, and there were several smaller holes after removing the thrombus (Supplementary Figure 5 ). To repair, a 5 × 10 cm bovine pericardial patch was chosen. This was sewn all around the right ventricular wall to eliminate the opening without narrowing the outflow tract. To repair the pseudoaneurysm, a 5 cm segment of the ascending aorta was replaced with a 34 mm gelweave straight graft.
Surgical pathology findings were suggestive of an aortic wall with medial degeneration, fibrosis, and calcification, with evidence of previous surgery with suture material and fibrosis. Vascular intima was hyperemic with a 3.0 cm calcified area, and a 6.0 cm aggregate of red-brown blood clot was noted, consistent with aortic pseudoaneurysm.
Outcome
After the operative procedure, the patient had severe coagulopathy with extensive bleeding that required multiple rounds of blood products. Due to ongoing oozing a Cabrol fistula was used to drain all the blood into the right atrium. Due to continued severe right ventricular dysfunction, a right ventricular assist device was placed with a 10 mm graft to the posterior descending artery and venous drainage from the right groin cannula. The patient was taken to the ICU, critically ill, requiring IV pressor support with right ventricular assist device in place. Hemodynamic function declined postoperatively, and despite resuscitative efforts, bedside 2D echo showed LV function to be severely depressed. His family and clinical providers agreed that further escalation was futile, and the patient passed due to right heart failure and hemodynamic collapse soon after aggressive resuscitative measures were de-escalated.
Discussion
This case represents an exceptionally rare and highly complex scenario involving a ruptured ascending aortic pseudoaneurysm with ARVF formation. Prior VSD repair surgery and aortic cannulation, combined with poorly controlled hypertension, likely led to the development of an iatrogenic aortic pseudoaneurysm, with progression ultimately leading to rupture and fistula formation.4,7,8
ARVFs in the setting of a VSD may arise from several etiologies, including congenital mechanisms such as rupture of a concomitant sinus of Valsalva aneurysm, acquired causes like infective endocarditis, or iatrogenic trauma.4,5 In this case, the location of the pseudoaneurysm adjacent to the prior surgical site supports an iatrogenic etiology. An additional factor potentially contributing to aneurysm progression in this patient was chronic substance use. Cocaine, in particular, is associated with transient hypertension, vasospasm, and direct vascular toxicity, which may exacerbate wall stress and accelerate aneurysmal degeneration. Methamphetamine and tobacco use may have also compounded endothelial injury and inflammatory changes within the aortic wall, heightening the risk of rupture or fistula formation.8,9 Recognition of these modifiable risk factors is essential in the longitudinal care of such patients. TTE often provides the first clue to the presence of an ARVF, revealing abnormal continuous flow across the interventricular septum. Transesophageal echocardiogram offers superior spatial resolution to localize the fistulous origin and its relation to the aortic cusps and prosthetic material. Cardiac CT angiography is valuable in defining the anatomic course and morphology of the fistula, as well as in distinguishing pseudoaneurysm formation. Cardiac catheterization remains the gold standard for hemodynamic assessment and direct visualization of the fistulous communication, aiding in therapeutic planning.10,11
Management of an aortic pseudoaneurysm with contained rupture and fistulous communication is complex and must be individualized. Surgical repair remains the gold standard, offering definitive exclusion of the aneurysm and closure of the fistula. However, redo sternotomy and repair in the setting of prior cardiac surgery carries significant perioperative risk, especially in patients with comorbidities or ongoing substance use.8,9 In selected high-risk cases, endovascular approaches have emerged as an alternative, particularly for descending thoracic aneurysms.12 Nonetheless, the proximity of this aneurysm to the aortic root and the involvement of the right ventricular outflow tract make endovascular exclusion technically challenging and potentially hazardous. However, the rapid deterioration in the present case necessitated emergent surgical intervention. Large aorto-RV fistulas, such as in the present case, often result in significant anatomic left-to-right shunt and result in right ventricular pressure overload and eventual RV failure.6
Management of aortic pseudoaneurysm with aorto-RV fistula mandates a multidisciplinary approach encompassing cardiology, cardiothoracic surgery, and critical care. Surgical repair remains the definitive treatment, particularly in cases complicated by rupture or hemodynamic compromise. The timing of ARVF intervention is guided by the size of the fistulous tract, symptom burden, and hemodynamic impact. Conservative management with aggressive blood pressure control may be reasonable in selected hemodynamically stable patients or when reversible contraindications to surgery exist, such as acute substance intoxication, as in our patient. However, progressive hemodynamic instability, expanding aneurysmal size, or overt fistulous flow mandates urgent operative intervention.13,14
The sudden onset of cardiogenic shock in our patient is consistent with the rapid hemodynamic deterioration often seen in aorto-RV fistula cases. The prognosis for patients with aorto-RV fistula varies, with some examples of cases successfully managed through either percutaneous interventions or patch repair versus open surgical repair.7,13,15 Emergent surgical repair of a ruptured aortic aneurysm with aorto-RV fistula is extremely challenging and carries a high mortality risk.14
Conclusion
This case highlights several critical lessons. First, the development of a focal ascending aortic pseudoaneurysm following prior surgical manipulation underscores the importance of long-term imaging surveillance in patients with prior aortic or septal interventions. Second, clinicians should maintain a high index of suspicion for aorto-RV fistula in patients presenting with unexplained right-sided volume overload or new continuous murmurs following prior cardiac surgery or instrumentation. Finally, optimal timing of surgical repair, balancing the risks of emergent surgery against stabilization from comorbid factors such as drug-induced vasospasm or hypertension, remains a nuanced, patient-specific decision best made within a multidisciplinary heart team framework.